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With 207,484 views on Sunday, 8 July 2018 our article of the day is Cave of the Crystals.

Cave of the Crystals or Giant Crystal Cave (Spanish: Cueva de los Cristales) is a cave connected to the Naica Mine at a depth of 300 metres (980 ft), in Naica, Chihuahua, Mexico.

The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found. The cave's largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot, with air temperatures reaching up to 58 °C (136 °F) with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors. Without proper protection, people can only endure approximately ten minutes of exposure at a time.The cave was discovered by the brothers Eloy and Javier Delgado.

A group of scientists known as the Naica Project have been heavily involved in researching these caverns.

This recording reflects the Wikipedia text as of 01:34 UTC on Monday, 9 July 2018.